Improved pump for low-pressure steam-engines



UNITED STATES PATENT OFFICE.

JOHN VIAL, OF CLEVELAND, OHIO.

Specification forming part of' Letters Patent No. 36,43 l, datedSeptember 9, 1362.

T0 all whom it may concern.-

Be it known that I, JOHN VIAL, of Cleveland, in the county of Cuyahogaand State of Ohio, have invented new and useful Improvements inLow-Pressure Steam-Engine Pumps; and I do hereby declare that thefollowing is a full and complete description of the construction andoperation of the same, reference beinghad to the accompanying drawings,making part of this speeeiication, in which- Figure I is a perspectiveView. Fig. 2 is a vertical section. Fig. 3 is a horizontal section inthe direction of the line ao x in Fig. 2. Fig. 4 is a horizontal sectionin the direction of the line y y in Fig. 2.

The nature of this improvement consists in such a construction of thepiston that a continuous iiow of water is produced during the ascent ofthe piston-head.

Thenecessity for animprovement in the construction ofthe air-pump7 (socalled) for lowpressure steam-engines has long been ielt by everypractical engineer, and the difficulties which have existed and do existin the use of the ordinary construction is made'apparent by stating thesingle fact that the ascending' piston-head carries with it the contentsof the pump-cylinder, the water reaching and reacting upon the head ofthe cylinder at the moment the pistou-head is at its greatest speed,

and consequently producing a severe concussion or shock. This concussionis often so Violent in fast-Working engines as to break through the headof the cylinder and otherwise injure the machinery.

It is the obj ect of myimprovement to cause a constant flow of waterthrough the exit-pipe while the piston is rising throughoutits wholeupper stroke, as hereinafter explained.

For the purpose of relieving the condensing-chamber from an excess ofwater when the engine is rst started, and also for causing a partialvacuum in the condensingchamber While at Work, the pump is constructedwith double capacity. In this manner a few strokes will clear thecondensing-chamber from its eX- eess of water.

The eXausting-chamber is constructed in the usual form, theinduction-pipe A, Fig. 2, leading therefrom to the pump-'cylinder B. AtO is seen the guard thatsupports the lower valve,

D. This valve is represented as being open, the upper side of whichrests upon the under side of the guard C. When this valve is closed, itrests upon the valve-seat, the position of which is indicated by the redline Y Y. The outer edge of this valve is indicated by the red circularline o in Fig. 4. The valve when closed covers the holes E E in Figs. 2and 4.

The piston-head is seen at F. This is also furnished with valveslikethose just described, and seen at G G. They are represented as beingclosed, in which position they are always found when the piston isrising.

In the ordinary mode of construction the piston-head is'worked by acommon pistonrod; but in my improved mode, instead of the Commonpiston-rod, I introduce a hollow trunk or cylinder, H, having a diametersufiicient to fill half of the area of the pump-cylinder. At the pointof union of this with the piston-head it is made of such 'form as toserve the purpose of a guard for the valve G, as seen at g, Fig. 2. Fromthis point to g' this cylinder is turned straight and smooth and worksin the packing I, which is inclosed in the packingbox I. The hollowtrunk H is worked by a connecting-rod, K, which is attached bv aconnection, K', within the trunk H. u

Upon a line horizontal to the bottom of the exit-pipe L is another setof valves, M, which Y open into the chamber of the exit-pipe. Thesevalves open upward when the piston is rising and close when the pistondescends. The -valves are also shown in Fig. 3, which is a section ofthe pump at the line x w in Fig. 2, and prevent the water and air fromreturning back into the pump-cylinder.

The mode of operation of this pump is as follows: Suppose the engine tobe in a state of rest and the pump and induction-pipe filled with water,as is also the condensingchamber, it is necessary for the free andperfect working of the engine that the condensing-chamber should beproperly cleared from water by a few strokes of the engine. The pumpworking double the capacity (more or less) of the induction-pipe,willclear this space of its surplus water by a few strokes of the engine,but afterward Will only raise half its capacity, thus forming a partialvacuum in the condensing-chamber. The upward stroke of the pumpthroughthe valves M the moment the piston piston filling the pump-cylinder buthalf-full of water at every descent yof the piston this amount of Waterpasses through the Valves G in the piston-head, but as the space abovethe piston-head, when the piston-head is down, has onlyr half thecapacity of the whole solid contents of the pump-cylinder when thepiston is up, in consequence of the space being half occupied by thehollow piston-trunk H, the water which only half fills the cylinder whenthe piston is up will completely fill the space above the piston-headwhen the piston is down. Now, when the piston is down, the space abovethe piston-head being com# pletely lled with water, this Water commencesto move or is discharged at the exit-pipe begins to move upward, andconsequently no shock can be felt consequent upon the striking of thewater against the upper head of the pump-cylinder, as is the casein theusual form of construction, in which case the water does not begin tomove until the pistonheadis upon I The cylinder B, plunger H, andpiston-head i F, in combination with the valves D G M and induction-pipeA and exit-pipe L, these several parts being arranged and operating asand for the purpose specified.

JOHN VIAL.

Witnesses:

W. H. BURRIDGE, HENRY VOTE.

